Concrete-arch form.



T. R. ANDERSON.

CONCRETE ARCH FORM. APPucAloN FILED SEPTA Patented 24,1917.

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IN VENTOR TZ-ffdff ATTORNEYS Qu E S S E N T W wf Nmems versus co. Fuero-uma., wAsnwcrum n c R. ANDERSON. CONCRETE ARCH foam. APPLlCATmN FILED SEPT-19. 191()- Patented Apr. 24,1917.

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Bv il ATTORNEYS para* sans narrar onirica.

THOMAS R. ANDRSON, 0F OKLAHOMA, OKLAHOMA.

CONCRETE-ARCH FORM. i

Application led September 19, 1916. Serial No. 120,960.

To all whom t 'may concern:

Be it known that I, THOMAS It. ANDER- soN, a citizen of the United States, and a resident of Oklahoma, in the county of Oklahoma and State of Oklahoma, have invented certain new and useful Improvements in Concrete-Arch Forms, of which the following is a specification.

My invention relates to forms for the construction of concrete arches, circles, and the like, and among the objects thereof is the provision of span members which are readily adjustable to spans of different lengths having the same radius for the arc of the arch. Another object is the provision of cooperating angle bars for sustaining the span members during the arch construction, and another object is the provision of means for quickly and easily installing said span members and for as readily removingthe same after the arch is built.

My invention is fully described in the following specification., of which the accompanying drawings form a part, in which like characters refer to like parts in each of the views, and in which z* Figure 1 is a sectional view of a culvert the arch of which was built with my improved form;

F ig. 2 is a plan View of the form, with the planking partly broken away;

Fig. 3 is an elevation of a unit of the span members in position and ready for the reception .of bolts, not shown;

Fig. 4 is a similar view but showing an intermediate stage in the span member installation;

Fig. 5 is a similar View showing the adaptation of the span unit to a shorter span than shown in Figs. 3 and 4; and Fig. 6 is an enlarged section taken on the line 6 6 of F ig. 3.

Referring to the drawings, 7 represent the sides of a culvert or the piers of a bridge, shown as of concrete and along the upper inner corners thereof I arrange angle bars 8 as supports for the span members 9 which carry the planks or boards 10 upon which the concrete is deposited for forming the arch 11, posts 12 and a hand-rail 13 being illustrated also in Fig. 1, but these form no part of the invention.

Each span unit 9 consists of two similar members 14 curved on a desired arc of a Specification of Letters Patent.

Patented Apr. 24, 1917.

circle and formed of angle bars the vertical webs 15 of which are provided with bolt holes 16 to permit said members 14 to be bolted together, a plurality of these holes being provided whereby the span unit may be adjustable as to length, to build a short or long arch with the same unit, two different lengths of arches being illustrated in Figs. 3 and 5, and the outer ends of the members 14 are recessed in V-shape to fit on the angle bars 8.

At 17 I have shown a lever for spreading the members 14 of each unit, said lever having studs 18 in spaced relationship thereon, one on each side, adapted to enter predetermined holes 16 with the members 14 in the positions shown in Fig. 4 and, when said lever is swung to the left into the position shown in Fig. 3, the members 14 are moved longitudinally with respect to each other into operative positions with the bolt holes 16 in register ready to receive the bolts for securing the members 14 in the desired relationship.

When all the span units are in position, suitably spaced, the boards 10 are placed thereon and the concrete may then be poured on the sides or piers 7 and boards 10 and the arch may be completed. After completion and setting. the bolts may be removed from the span units and the levers 17 thrown into the position shown in Fig. 4, thereby permitting the ready removal of the said units and of the boards forming the concrete form, and the angles 8 may then be removed and the channels 19 filled with concrete if desired, although this is not necessary in culverts.

It will thus be seen that I provide a form adjustable to spans of different lengths, quickly installed and removed, easily operated by means of the levers 17, and comparatively inexpensive and. while I have shown certain preferred structural details, I do not limit myself thereto as I may make changes thereover provided such changes do not depart from the spirit of the invention and come within the scope of the appended claim.

Having fully described my invention, what I claim as new, and desire to secure bv Letters Patent, is :w-

As an article of manufacture, for use in a concrete arch form, a span unit consisting of two similar angle bar members of arcuate form arranged back to back and having the overlappingr ends of the vertical web members provided With a plurality of holes,

and a lever arranged between said members having oppositely disposed studs at opposite ends adapted to enter the respective Uopies of this patent may be obtained for ive cents each, by addressing the Washington, D. C.

holes to move said members longitudinally With respect to each other.

THOMAS R. ANDERSON.

Witnesses:

D. A.. BENNETT, LUTHER JONES.,

Commissioner of Intenta. 

